流化床中煤与稻秆混烧污染物排放特性  

Characteristics of pollutant emissions from co-combustion of straw and coal in fluidized bed

作　　者：谢兴旺 仲兆平[1] 薛则禹 XIE Xingwang;ZHONG Zhaoping;XUE Zeyu(School of Energy and Environment,Southeast University,Nanjing 210096,China)

机构地区：[1]东南大学能源与环境学院,南京210096

出　　处：《环境工程学报》2018年第9期2572-2579,共8页Chinese Journal of Environmental Engineering

基　　金：国家自然科学基金资助项目(51276040;U1361115);国家重点基础研究发展计划资助项目(2013CB228106)

摘　　要：在自主设计的流化床上开展煤与稻秆混烧的实验。通过对燃烧过程中烟气成分及飞灰含碳量的分析,研究了质量掺混比、燃烧温度、流化风速及二次风率对混烧的影响。实验结果表明,掺混稻秆有效改善了煤的燃烧特性,随着质量掺混比的增加,NO_x、SO_2及CO的排放浓度降低,飞灰含碳量降低。当掺混比由0%增加至30%、温度为850℃时,NO_x排放浓度由506.25 mg·m-3降低至404.33 mg·m^(-3),SO_2排放浓度由762.86 mg·m^(-3)降低至522.86 mg·m^(-3)。随着燃烧温度的增加,NO_x与SO_2排放浓度增加,而CO排放浓度和飞灰含碳量降低。随着流化速度的增加,NO_x与SO_2排放浓度增加,CO排放浓度和飞灰含碳量先降低后增加,并分别在流化速度0.234 m·s^(-1)和0.26 m·s^(-1)时达到最低。随着二次风率的增加,SO_2排放浓度与飞灰含碳量降低,NO_x排放浓度与CO排放浓度先减小后增加,均在20%二次风率时达到最低。Combustion experiments of coal and straw mixture were conducted in a lab designed fluidized bed.The effect of mixing ratio, bed temperature, fluidization velocity and secondary air ratio were studied by analyzing flue gas components and the carbon content in fly ash. The experimental results show that mixing straw can effectively improve the combustion characteristics of coal. With the increase of straw mass mixing ratio, the emission concentration of NOx, SO2 and CO decreases and the carbon content in fly ash decreases as well. In the condition of bed temperature at 850 ℃, when the mixing ratio were increased from 0% to 30%, the emission of NO_x reduced from 506.25 mg·m^（-3） to 404.33 mg·m^（-3） and the emission of SO_2 reduced from 762.86 mg·m^（-3） to 522.86 mg·m^（-3）.As the combustion temperature increased, the concentration of NOx and SO2 increased, while the CO emission concentration and fly ash content decreased. With the increase of fluidization velocity, NO_x and SO2 emission concentration increased, CO emission concentration and fly ash carbon content decreased first and then increased,and reached the lowest when the fluidization velocity was 0.234 m·s^（-1） and 0.26 m·s^（-1）. With the increase of the secondary air ratio, the emission of SO2 and the carbon content of fly ash decreased, the emission of NOx and CO first declined and then increased, and reached the lowest at 20% secondary air ratio.

关 键 词：混烧 流化床 稻秆 煤 

分 类 号：X511[环境科学与工程—环境工程]